DI Hum or DI hiss from balanced out

[mr_musica]

Hi, I have recently acquired an SVT3-PRO, have only used it a couple of times. I tried connecting to the DI balanced out and it was "hissing" so we pulled the ground lift switch but the technician said it didn't improve, so we went with a DI.

My question is, if there's any way to get the preamp from the ampeg into the mixing board in this situations?
Also, could it be that the hiss is from the bass itself? I suppose ground hum should sound like 60 hz hum, is high freq hiss also a ground issue?

 

[abarson]

From the manual, page 8: https://ampeg.com/pdf/SVT-3PRO_OM.pdf
"TRANSFORMER BALANCED LINE OUTPUTS: These jacks supply a balanced/unbalanced preamp output signal for connecting to a house mixing board, recording console or external amplifiers with balanced inputs. The signal can either be set to Pre- or PostEQ with the selector switch and its level is controlled by the line out level control."

The DI output is the correct interface to connect to a mixer or recording interface.
I'm assuming that this is not 60Hz hum, as the ground lift made no difference. The ground lift is necessary sometimes when the amp and mixer share the same ground plane. It's more likely that the line out level was too high for the other interface. Were you using a balanced cable, like a XLR microphone cable?

Is this hiss audible through a speaker? "Hiss" is usually higher frequency. It can be introduced by your bass if it isn't properly shielded.
Is the hiss present if you use a different bass through the rig? Just making suggestions to try and narrow the scope.

 

[mr_musica]

I was using and XLR microphone cable. The speaker didn't present that hiss. I was using an American Deluxe Jazz Bass with the active switch on. I tried moving the pan pot to have both pickups at full or having more of one pickup, but the only thing that kinda worked was rolling off the high in the amp...

My only other bass is an MIM passive P bass, I'm going to try that soon, but I want to try it out live, since the conditions are not the same as they are at home.

Thanks for your reply.

 

[ThisBass]

Turn up the signal for the preamp section with the gain knob till the clip led flashes occasionally.
Control the volume to your needs with the master knob.
With some "good luck" the hizz coming off of the DI should be gone.

 

[Old Garage-Bander]

From the manual, page 8: https://ampeg.com/pdf/SVT-3PRO_OM.pdf
"TRANSFORMER BALANCED LINE OUTPUTS: These jacks supply a balanced/unbalanced preamp output signal for connecting to a house mixing board, recording console or external amplifiers with balanced inputs. The signal can either be set to Pre- or PostEQ with the selector switch and its level is controlled by the line out level control."

The DI output is the correct interface to connect to a mixer or recording interface.
I'm assuming that this is not 60Hz hum, as the ground lift made no difference. The ground lift is necessary sometimes when the amp and mixer share the same ground plane. It's more likely that the line out level was too high for the other interface. Were you using a balanced cable, like a XLR microphone cable?

Is this hiss audible through a speaker? "Hiss" is usually higher frequency. It can be introduced by your bass if it isn't properly shielded.
Is the hiss present if you use a different bass through the rig? Just making suggestions to try and narrow the scope.

Hum happens with ground loop problems. Hiss is usually something else.